1. Field of the Invention
The present invention relates to electrical connectors and, more particularly, to a socket connector for receiving terminals from a mating component.
2. Brief Description of Earlier Developments
U.S. Pat. No. 5,044,973 discloses an electrical connector for receiving male contacts of an electrical component. The connector has preload pins to preload arms of electrical contacts of the connector in an open position. U.S. Pat. No. 5,704,800 discloses an inner wall projection of a housing used to preload a contact arm.
One of the problems in the design of high pin count connectors is the amount of force that is required to mate the connectors. A minimum amount of normal force (approx. 30 grams per contact) is required for a reliable contact interface for gold plated contacts. Usually most applications limit the total mating forces to less than 10 lb for repetitive operations. This means that there is finite limit, based on the sliding friction alone, to the maximum pin count for a standard connector; around 450 contacts at the minimum normal force. However, this does not take into account the increased friction at the initial part of the contact mating cycle; when the contact is first opened. This additional force approximately doubles the initial forces which further limits the pin count. In other words, even less than 450 contacts will exceed the mating force limit.
Fortunately, there have been developed a number of techniques to allow large numbers of pins to be mated. One of these methods is ZIF, which means that either small or almost no xe2x80x9cZ-axisxe2x80x9d forces are required to mate the connector. This typically is done in two basic ways. In one case the contacts are xe2x80x9cnormally openxe2x80x9d and are cammed into contact position using an external plate. In other cases the contacts are xe2x80x9cnormally closedxe2x80x9d and they are temporarily cammed open and then closed after insertion of a pin. Both of these designs share the problem of having sufficient contact xe2x80x9cwipexe2x80x9d to remove films and contaminants. Another method is to use some form of mechanical advantage to drive the pin assembly laterally into a contact, eliminating xe2x80x9cZ-axisxe2x80x9d forces and having sufficient contact wipe to maintain reliability. Typically, the mechanical advantage of a lever driving the pin assembly can reduce the mating forces to acceptable levels. However, historically these mechanisms have not been easy to design and implement. The designs typically have had problems with flexing and bowing resulting in hystersis in the connector assembly. Recent requirements of higher pin counts (600+pins) coupled with changes of density from 0.100 centers to 0.050 centers, in addition to requirements for lower mating heights, make these problems even more difficult to solve.
In accordance with one embodiment of the present invention, an electrical connector is provided comprising electrical contacts and a housing. The electrical contacts are connected to the housing. The housing comprises a first housing member and a second housing member movably connected to the first housing member. The second housing member comprises holes for allowing terminals of an electrical component to be inserted into the housing. The housing also comprises contact preload projections. The contact preload projections engage the electrical contacts to preload the electrical contacts and, when the terminals are inserted into the holes, the contact preload projections contact the terminals to form a strain relief support for the terminals.
In accordance with another embodiment of the present invention, an electrical connector and electrical component assembly is provided comprising an electrical component comprising male contacts; and an electrical connector for connecting the electrical component to another electrical component. The electrical connector comprises electrical contacts and a housing. The housing comprises first and second housing members movably connected relative to each other. The electrical contacts are connected to the first housing member. The second housing member comprises contact preload sections contacting the electrical contacts and apertures having the male contacts therein. The contact preload sections having a width less than a width of the male contacts. The contact arms of the electrical contacts are deflected outward by the male contacts as the electrical contacts move off of the contact preload sections onto the male contacts.
In accordance with another embodiment of the present invention, an electrical connector is provided comprising electrical contacts and a housing. The housing comprises first and second housing members movably connected to each other. The electrical contacts are mounted to the first housing member. The second housing member comprising a first section and contact preload sections extending from the first section. The second housing member has apertures through the first section and into the contact preload sections. Side openings are provided at the contact preload sections into the apertures.
In accordance with one method of the present invention, a method of connecting male contacts to electrical contacts in an electrical connector is provided comprising steps of inserting the male contacts in a first direction into holes in a housing of the electrical connector; and moving the male contacts in a second different direction, with a portion of the housing, into contact with electrical contacts of the electrical connector. The electrical contacts are preloaded against preload sections of the portion of the housing, the preload sections having a width smaller than a width of the male contacts and, during the step of moving, the male contacts deflect contact arms of the electrical contacts outward as the electrical contacts move off of the preload sections onto the male contacts.